[Telestrat] chdir management (#1419)

* add syschdir

* revert read.s

* remove extra line

* Now we update __cwd

* Fix tab

* Fix another tab

* Fix tab

* Fix tab and jmp

* fix xgetcwd

* Fix comments

asminc/telestrat.inc

@@ -284,6 +284,8 @@ XSOUND           = $44
 XMUSIC           = $45 
 XZAP             = $46          ; Send Zap sound to PSG
 XSHOOT           = $47
+XGETCWD          = $48          ; Get current CWD
+XPUTCWD          = $49          ; Chdir
 XMKDIR           = $4B          ; Create a folder. Only available in TELEMON 3.x (bank 7 of Orix)
 XRM              = $4D          ; Remove a folder or a file. Only available in TELEMON 3.x (bank 7 of Orix)
 XFWR             = $4E          ; Put a char on the first screen. Only available in TELEMON 3.x (bank 7 of Orix)

libsrc/telestrat/initcwd.s

@@ -10,8 +10,7 @@
 
 
 initcwd:
-        ldx     #PWD_PTR
-        BRK_TELEMON XVARS
+        BRK_TELEMON(XGETCWD)
 
         sta     ptr1
         sty     ptr1+1

libsrc/telestrat/read.s

@@ -12,21 +12,21 @@
 ;int read (int fd, void* buf, unsigned count);
 
 .proc   _read
-    sta     ptr1 ; count
-    stx     ptr1+1 ; count
-    jsr     popax ; get buf
+
+    sta     ptr1           ; Count
+    stx     ptr1+1         ; Count
+    jsr     popax          ; Get buf
 
     sta     PTR_READ_DEST
     stx     PTR_READ_DEST+1
-    sta     ptr2 ; in order to calculate nb of bytes read
+    sta     ptr2           ; In order to calculate nb of bytes read
     stx     ptr2+1 ;
 
-    ; jsr popax ; fp pointer don't care in this version
 
     lda     ptr1 ;
     ldy     ptr1+1 ;
     BRK_TELEMON     XFREAD ; calls telemon30 routine
-    ;  compute nb of bytes read
+    ;  Compute nb of bytes read
     lda     PTR_READ_DEST+1
     sec
     sbc     ptr2+1

libsrc/telestrat/syschdir.s

@@ -0,0 +1,32 @@
+;
+; Jede (jede@oric.org), 2021-02-22
+;
+; unsigned char _syschdir (const char* name, ...);
+;
+
+        .export         __syschdir
+        .import         addysp, popax
+        .importzp       tmp1
+        .import         initcwd
+
+        .include        "telestrat.inc"
+        .include        "zeropage.inc"
+        
+
+__syschdir:
+        ; Throw away all parameters except the name
+        dey
+        dey
+        jsr     addysp
+
+        ; Get name
+        jsr     popax
+		
+        stx     tmp1
+        ldy     tmp1
+        
+        ; Call telemon primitive
+        
+        BRK_TELEMON(XPUTCWD)
+
+        jmp     initcwd      ; Update cwd